Makes cache writes atomic

[arcanis]

Investigating why we sometimes have Invalid zip errors and inconsistent fetch data:

➤ │ Resolved 1716 packages, fetched 1294 packages (367.86 MiB)
➤ │ Resolved 1716 packages, fetched 1295 packages (368.03 MiB)

I noticed the cache writes aren't atomic, which could be related.

[github-actions]

⏱️ Benchmark Results

gatsby install-full-cold

Metric	Base	Head	Difference
Mean	2.304s	2.299s	-0.21% ✅
Median	2.292s	2.305s	+0.55% ⚠️
Min	2.215s	2.162s
Max	2.489s	2.400s
Std Dev	0.066s	0.057s

📊 Raw benchmark data (gatsby install-full-cold)

Base times: 2.460s, 2.489s, 2.237s, 2.228s, 2.301s, 2.306s, 2.356s, 2.259s, 2.265s, 2.377s, 2.380s, 2.306s, 2.300s, 2.215s, 2.274s, 2.354s, 2.296s, 2.304s, 2.324s, 2.288s, 2.228s, 2.260s, 2.233s, 2.272s, 2.326s, 2.238s, 2.288s, 2.385s, 2.274s, 2.286s

Head times: 2.296s, 2.162s, 2.304s, 2.333s, 2.309s, 2.296s, 2.341s, 2.244s, 2.310s, 2.235s, 2.195s, 2.278s, 2.359s, 2.385s, 2.397s, 2.215s, 2.400s, 2.310s, 2.325s, 2.367s, 2.306s, 2.300s, 2.308s, 2.277s, 2.348s, 2.257s, 2.266s, 2.238s, 2.335s, 2.269s

---

gatsby install-cache-and-lock (warm, with lockfile)

Metric	Base	Head	Difference
Mean	0.351s	0.362s	+3.30% ⚠️
Median	0.351s	0.353s	+0.71% ⚠️
Min	0.344s	0.350s
Max	0.362s	0.593s
Std Dev	0.004s	0.044s

📊 Raw benchmark data (gatsby install-cache-and-lock (warm, with lockfile))

Base times: 0.344s, 0.347s, 0.345s, 0.347s, 0.348s, 0.346s, 0.345s, 0.346s, 0.347s, 0.350s, 0.349s, 0.350s, 0.348s, 0.353s, 0.351s, 0.352s, 0.351s, 0.355s, 0.354s, 0.352s, 0.349s, 0.354s, 0.354s, 0.355s, 0.362s, 0.358s, 0.353s, 0.355s, 0.352s, 0.354s

Head times: 0.351s, 0.354s, 0.357s, 0.359s, 0.354s, 0.353s, 0.355s, 0.354s, 0.593s, 0.351s, 0.350s, 0.356s, 0.352s, 0.352s, 0.351s, 0.353s, 0.352s, 0.356s, 0.354s, 0.357s, 0.355s, 0.350s, 0.350s, 0.354s, 0.350s, 0.355s, 0.353s, 0.353s, 0.353s, 0.384s